1. Field of the Invention
The present invention relates to an electric compressor controller that controls operations of the electric compressor provided in an air conditioning system for a vehicle.
2. Description of Related Art
A conventional control for an electric compressor is disclosed in Japanese Patent Application Laid-Open No. 2008-290523 (Patent Document 1). In this Patent Document 1, it is disclosed that outside air introduced form an outside of a vehicle is heated by a condenser and then introduced into a compartment. Then, heat is collected by a condenser from inside air to be discharged from the compartment is discharged and then the air is discharged to an outside of the compartment. Here, an operation of the compressor is stopped when room temperature is low. In this control, the heat is collected from the air to be discharged from the compartment and dehumidification is functioned even in an extremely low temperature state where a heat pump operation cannot be done due to negative suction pressure of refrigerant suctioned to the compressor.
In addition, another conventional control for an electric compressor is disclosed in Japanese Patent Application Laid-Open No. 2009-264206 (Patent Document 2). In this Patent Document 2, it is disclosed that heating is done by a heat pump operation and refrigerant is heated by Joule heat of an inverter when temperature of the refrigerant is low. In this control, dehumidification is done by increasing loss of the inverter without reversing heat pump cycle (without refrigeration cycle) if an external radiator is frosted.